Effect of particle size of whiskers on preparation and properties of macroporous K ₂Ti ₆O ₁₃ ceramics

The K ₂Ti ₆O ₁₃ macroporous ceramics were prepared by the dry pressing method with raw materials of K ₂Ti ₆O ₁₃ whiskers, K ₂CO ₃ and TiO ₂ powers, and the pore structure was controlled by changing the length of K ₂Ti ₆O ₁₃ whiskers and using accumulation of whiskers with different sizes. The relationship among particle size, ratios of whiskers with different particle sizes and properties of permeability and bending strength of porous K ₂Ti ₆O ₁₃ ceramics were investigated. The results showed that the bulk density and bending strength of K ₂Ti ₆O ₁₃ porous ceramics increased with the decrease of particle size of K ₂Ti ₆O ₁₃ whiskers, while the behavior of porosity and permeability was the opposite. When K ₂Ti ₆O ₁₃ porous ceramics were prepared by using accumulation of K ₂Ti ₆O ₁₃ whiskers with different sizes whose length was D ₅₀=7.50 μm and 1.60 μm, the corresponding mass ratio was 3:1, the framework of K ₂Ti ₆O ₁₃ ceramics were connected with the long whiskers and the medium or small particles. The K ₂Ti ₆O ₁₃ ceramics exhibited optimal properties as follows: bending strength of 42. 8±0. 2 MPa, pure water flux of 2366 L·m ^-2·h ^-1·MPa ^-1 and open porosity of 36.4%, respectively. The performance of K ₂Ti ₆O ₁₃ porous ceramics prepared from whiskers with different sizes was better than that of ceramics with uniform whiskers in terms of permeability and bending strength. This material showed excellent potential in the area of molecular sieve membrane.